Endorsements that coordinate Commercial Package Policy (CPP) coverages to avoid duplication are known as:

Interline endorsements are designed specifically to amend or coordinate coverages within a Commercial Package Policy (CPP) to prevent duplication or overlap of coverage. They serve to streamline various coverages by providing definitions, exclusions, or adjustments that apply across multiple lines of insurance within the same policy. This ensures that businesses have a coherent and comprehensive set of coverages without redundant protections being afforded by different sections of the policy. By consolidating similar terms or conditions, interline endorsements enhance clarity and efficiency in policy management.

Other options do not fulfill this specific function. For example, supplementary coverages generally refer to additional benefits that can be added to a policy, and special endorsements may refer to unique changes or specific coverages added to a policy rather than coordinating existing coverages. Common endorsements may imply a general use but do not specifically indicate their role in avoiding coverage duplication in a CPP context.